1. Field of the Invention
This present invention concerns a device for the assembly of standard elements intended for the creation of precision mechanical structures.
2. Description of Related Art
It applies in particular, but not exclusively, to the creation of tools for the gripping of mechanical parts intended in particular for the automobile industry. It is usable in particular on assembly lines for parts of the bodywork of automobiles which require gripping tools or grippers, which are firmly attached to fixed supports or mobile supports such as the heads of robots. It is used to position, with precision and in a repeatable manner, the aforementioned mechanical parts during their assembly on automobile assembly lines. It also allows said grippers to conform to the nature of the mechanical parts to be processed and to the type of operation to be performed on said mechanical parts.
We know in fact that such grippers are designed and manufactured to order in accordance with the nature of the mechanical parts to be processed, and in particular with their geometry, with the type of operation to be performed, and especially with the trajectories to be followed by said mechanical parts.
These grippers are generally manufactured in steel or aluminium alloy tubing, or in aluminium alloy bar. The dimensions of these connecting elements are determined by the loads to be supported and by the precision of the positioning required. As such, they therefore constitute tools which have to be matched to specific requirements, and which necessitate a high degree of rigidity combined with the lowest possible mass. As a consequence, their production cost is high, because the process is one which can be described as artisanal, given the diversity of the mechanical parts to be employed. In addition, in the event of failure or of damage, the stocking of such grippers constitutes an additional cost, greatly increasing their repair costs.
In order to remedy these drawbacks, the invention proposes to create grippers from arms which are firmly attached to a support block, such arms being implemented in the shape of an assembly of sections of extruded aluminium alloy bar which has been processed so as to obtain the desired shape.
This solution allows the weight of the gripper to be reduced while also providing a certain rigidity that guarantees the required precision and repeatability. It also results in less costly maintenance, in view of the ability to replace any defective elements. Finally, it allows the gripper to be reconfigured in order to make it compatible with different mechanical parts.
The drawback of this type of gripper results from the method of assembly of the bar sections, which is performed using assembly bolts and centring pins. Such an assembly method leads to high production costs for the pin housings and for the threaded orifices, as well as high assembly costs for the mating of the pins with their housings and the number of tightening operations necessary.
Given the problems mentioned above, the invention particularly has the aim of facilitating the assembly operations and reducing the costs associated with the production and assembly operations.